Interesting read and from what I can tell, a lot of the information is based on detective work, rather than insider information. It’s quite interesting seeing work-in-progress Microsoft UI elements that never made it into production releases.

The Vista development cycle is pretty interesting. I found it funny that after shipping, many of Vista’s ideas and implementations (like SideShow) quickly became obsolete when the iPhone released days earlier. Many of these concepts (like “castles” and a simple device manager in Explorer) also ended up in 7 post-Vista.